The present invention generally relates to self-storing awning assemblies for recreational vehicles and is more particularly directed to boxed awnings, including lateral arm support awnings, which include a roller for automatically retracting a awning into the box, or frame.
When closed, it is necessary that the box containing an awning be sealed in order to prevent undesirable wind noise during operation of the vehicle. It should be appreciated that if the awning is not contained in the box or frame in a sealed manner, any gaps occurring will act as an annoying source of sound when air rushes past at speeds up to 70 mph. Further, undo stress may be induced due to such wind buffeting thus being a source of potential damage.
When new, such sealed awning boxes function properly, however, during usage, the awning material typically stretches, which causes a problem with regard to the system for extending and retracting the awning. Typical fabric stretch amounts to 2-3% of fabric length, or more, and this relates to up to 3 inches or more for a 10 foot awning.
This problem is set forth in U.S. Pat. No. 4,615,373. When the awning stretches, typical control systems cannot accommodate for the extra length of awning and consequently, the retraction of the awning is stopped before the awning is entirely within the box or frame and sealed therein to prevent any gaps.
U.S. Pat. No. 4,615,371 provides for adjustment of limit switches so that a drive motor does not need to be shut off prematurely.
Other systems include counters, or stepper motors, for controlling the start and stop positions of the awning relative to the box during the extension and retraction. These systems are not amenable to accommodating for awning stretch.
The present invention provides for an automatic lateral arm awning system for recreational vehicle which accommodates for awning material stretch in order to insure sealing of the awning within a frame in order to prevent wind generated noise during movement of the recreational vehicle.
An automatic lateral arm awning system for a recreational vehicle in accordance with the present invention generally includes awning material having a first and a second end with a roller secured to the material first end for wrapping the awning material thereabout.
A header is provided and secured to the material second end and a frame is provided for enclosing the roller and awning material and sealing with the header in order to prevent wind generated noise upon driving of the recreational vehicle.
Arms interconnect the frame and the header and may be spring loaded for urging the header away from the frame upon rotation of the roller in one direction and an electric motor disposed within the roller is provided for rotating the roller. The awning material unrolls from the roller and extends outwardly from the frame upon rotation of the roller in one direction and wraps around the roller upon rotation of the roller in an opposite direction.
Importantly, means are provided for accommodating for awning material stretch in order to insure sealing between the header and the frame. This means includes a control circuit for determining motor current and stopping the electric motor upon an increase in motor current greater than an operating current for rotation of the roller in the opposite direction.
The control circuit may be configured for shutting off current to the electric motor upon stalling of the electric motor or upon a preset increase in current draw. That is, the motor control circuit determines the current during operation of the electric motor and stops rotation of the roller upon sealing of the header with the frame.
A method in accordance with the present invention for an automatic lateral arm awning system for recreational vehicle generally includes the steps of providing awning material having a first and second end, securing a roller to the material first end for wrapping around the awning material and securing a header to the material second end.
Method further provides for enclosing the roller and awning material with a frame and sealing the frame with the header in order to prevent wind generated noise upon driving of the recreational vehicle.
The frame and the header may be interconnected by a pair of spring-loaded arms for urging the header away from the frame upon rotation of the roller in one direction. The method further includes disposing an electric motor within the roller for rotating the roller.
In one embodiment, the method still further provides for accommodating for awning material stretch in order to insure sealing between the header and the frame by determining motor current and stopping the electrical motor upon an increase in motor current greater than an operating current for rotation of the roller and during retraction of the awning.
More particularly, the step of determining motor current may include waiting for a period of time until the motor reaches a steady state running speed and thereafter sampling the motor current after the waiting period. Alternatively, the step of stopping the electric motor may include stopping the motor upon stalling thereof due to increase loading during a sealing between the header and the frame.